The present invention relates to gearboxes, and more particularly to gearboxes for use in gas turbine engines.
In some gas turbine engines, an intermediate case is utilized between compressor stages, such as between a high-pressure compressor (HPC) stage and a low-pressure compressor (LPC) stage. Additionally, a gearbox is typically used for powering auxiliary components, such as generators and oil pumps, for example. The conventional gearbox has a single lobe, limiting the location of all accessories mounted on the gearbox to approximately the same location. Conventionally, such gearboxes are connected to a horizontally extending lay shaft, which is connected to a vertically extending tower shaft, which in turn is connected to and rotated by a compressor shaft. Such gearboxes are typically located toward the aft of the gas turbine engine, requiring a long lay shaft adding weight to the engine. Moreover, locating a gearbox near the aft of the engine exposes the gearbox to a relatively high temperature environment and further crowds an already crowded section of a typical gas turbine engine.